Combined propelling and steering device for screw propelled ships



. L. KORT Dec. 6, 1938.

2,139,594 COMBINED PROPELLING AND STEERING DEVICE FOR SCREW PROPELLED SHIPS Filed June 25, 1937 INVENTOR. L. Karl ORNEYS.

UNITED STATES PATENT OFFICE COMBINED PROPEILING AND STEERING DEVICE FOR SCREW PROPELLED SHIPS Ludwig Kort, Hanover, Germany Application June 25, 1937, Serial No. 150,398

In Germany February 8, 1936 7 Claims. (01. 114-166) The present invention relates to means for imship and the propeller showing in section the proving the propulsion and steering of ships and surrounding nozzle. more particularly pertains to an arrangement Figure 2 is a rear view of the ship and the wherein a tubular nozzle is swingably mounted nozzle rudder showing the propeller arranged adjacent the propeller so that the nozzle serves therein. 5

as a steering device and also acts to increase the Figure 3 is a front view of the nozzle body. thrust of the propeller. Fig. 4 is a plan-view of the arrangement shown In my U. S. Patent 2,030,375 a device is disin Figures 1 and 2, indicating in horizontal cross closed showing how the propelling eil'ect of a sectiontaken about in height of the propeller ships screw propeller may be improved by arshaft-the nozzle body. 10 ranging a tubular ring around the blades of the In the various figures the same numerals refer propeller. The inner part of the tube is shaped to the same parts. (I) indicates the stern of a like a nozzle, having its entering opening in front ship with the deck-line indicated at (2). (3) of the propeller, while the walls of the ring have is the nozzle body with the propeller (4) arl5 profiles comparable with the profiles of the wings ranged therein at or near to its narrowest inner of an aeroplane. The suction side oi. the profiles cross section and with but little clearance be- (upper side of the wing) is turned towards the tween the wing tips of the propeller and the surpropeller, and the pressure side (underside of the rounding walls of the nozzle. The mouth of the wing) forms the outside of the nozzle body. The nozzle body is well rounded ofi at the entering entering edges of the profilesthe mouth of the edge 5. (6) is the rudder shaft and ('l) the lower 20 nozzleare well rounded oil. The ring is conrudder pintle. The rudder-shaft and the pintle nected to the ship and the propeller works indeare rigidly connected to the nozzle ring and pivpendently therein at or near to the narrowest otably supported by the top-bearing (8) and the cross sectional area of the nozzle with but little lower bearing (9), the latter being connected to clearance between the wing tips of the propeller a heel piece on the stern post. The rudder shaft 25 and the surrounding walls of the nozzle. (6) is connected in the usual manner to a steer- As long as the nozzle forms part of the ship's ing gear so that the shaft and the nozzle conhull, or is rigidly connected to the same, it is nected thereto may be turned at various angles necessary for steering purposes to arrange a in exactly the same way as is usual in connecseparate rudder on the ship which is usually 10- tion with ordinary rudders. 30

cated behind the exit opening of the nozzle. It In most cases it is necessary, in order to acis, however, possible and found practical in some commodate a large propeller, that the walls of cases to combine the action of the nozzle with the nozzle ring should be given a slender cross the action of a rudder, by employing the sosection in the upper and lower part of the ring,

called ring-rudders" around the propeller, which while the mouth of the nozzle should be made 35 do not produce additional thrust. rather wide, in order to catch as much water It is, therefore, an object of my present inas the propeller can accelerate towards the rear vention to provide such a combined device. A at the service speed of the ship. The total 1rmore specific object of the present invention is tical height (l0) of the nozzle body therefore s to provide a combined propelling and steering usually made smaller than the total width (ll). 40 device on screw propelled ships consisting of a In order to avoid at the slender portions of the screw propeller surrounded by a tubular shaped ring the danger that the incoming water may nozzle as described by my U. S. Patent 2,030,375, separate from the inner walls of the nozzle and wherein pivoting means are provided between the thereby disturb the propelling effect of the noznozzle and the ship's hull allowing the nozzle to zle, it is advisable to carry the mouth of the 45 be turned with respect to the ship like a rudder. nozzle at the slender portions of the nozzle ring It is a further object of my invention to infurther forward than that of the side portions of dicate what additional arrangements are adthe ring, where the thicker airfoil cross sections visable in order to adapt the nozzle for efiectiveof the walls are arranged. This is indicated in ly answering the combined purpose of increas- Figure 4 by the outside bottom-line ([2) of the 50 ing the propelling thrust and the steering acmouth of the nozzle and by the foremost point tion. (ii) of the nozzle body shown in Figure 1.

In the accompanying drawing the invention is For improving the rudder action of the nozzle shown by way of example. during the forward motion of the ship, and fur- Figure l is a side elevation of the stern of a thermore with a view to turn as far as possible 55 the cork-screw motion of the water which is leaving the propeller, into a reaction producing useful thrust a vertical guide fin (i4) --and eventually also a horizontal guide fin (ID-is arranged in the outlet opening of the nomle body. In order to have a similar efiect during the astern motion of the ship, radially arranged guide fins (l6) may also be fitted on the inside of the nozzle in front of the propeller, as is indicated in Figures 1, 3 and 4.

In order to eliminate whirling losses between the adjoining faces of the outside of the nozzle body and the opposite wall of the ship's hull both may be mutually so shaped that there is but little clearance between them and the outside 'of the nozzle body and the adjoining outside of the ship are homogeneously merging into each other, when viewing them as a fair-lead for the passing water.

While the drawing illustrates the combined nozzle and rudder for side-steering of a singlescrew ship, it is, of course, possible to apply the same device in an analogous way to twin-screw ships, and not only for side-steering but also for producing vertical movements of a ship, as may be required for a submarine. In the latter case the turning axis of the rudders must be arranged horizontally instead of vertically as shown in the drawing.

What I claim is:-

1. A steering and propelling device for a screw propelled ship comprising in combination, a tubular nozzle surrounding the propeller with the approximate longitudinal center thereof arranged adjacent the turning plane of the propeller blades, the internal dimension of the nozzle being such as to provide a relatively small clearance between the inner surface of the nozzle and the tips of the propeller. blades, means carried by the stern of the ship for pivotably supporting the nozzle, the axis of the pivot supporting means extending through the propeller shaft and adjacent the turning plane of the propeller blades, the inner surface of the nozzle being so shaped that the cross sectional area behind the propeller does notlchange materially when the longitudinal axis of the nozzle is in alignment with the axis of the propeller shaft, the inner surface of the nozzle being enlarged sharply in front of the propeller to provide an entrance opening at the front edge which is substantially larger in cross sectional area than the exit opening, and the walls of the nozzle having airfoil profiles with well rounded entering edges.

2. A steering and propelling device for a screw propelled ship comprising, a tubular nozzle surrounding the propeller with the approximate longitudinal center thereof arranged adjacent the turning plane of the propeller blades, the internal dimension of the nozzle being such as to provide a relatively small clearance between the inner surface of the nozzle and the tips of the propeller blades, means carried by the stern of the ship for pivotably supporting the nozzle, the axis of the pivot supporting means extending through the propeller shaft and adjacent the turning plane of the propeller blades, the inner surface of the nozzle being so shaped that the cross sectional area behind the propeller does not change materially when the longitudinal axis of the nozzle is in alignment with the axis of the propeller shaft, the inner surface of the nozzle being enlarged sharply in front of the propeller to provide an entrance opening at the front edge which is substantially larger in cross sectional area than the exit opening, the walls of the nozzle having airfoil profiles with well rounded entering edges, and the longitudinal distance of said edges from a transverse plane through the axis of the pivotable supporting means being less than the radius of the propeller.

3. A steering and propelling device for a screw propelled ship comprising, a tubular nozzle surrounding the propeller with the approximate longltudinal center thereof arranged adjacent the turning plane of the propeller blades, the internal dimension of the nozzle being such as to provide a relatively small clearance between the inner surface of the nozzle and the tips of the propeller blades, means carried by the stern of the ship for pivotably supporting the nozzle, the axis of the pivot supporting means extending through the propeller shaft and adjacent the turning plane of the propeller blades, the inner surface of the nozzle being so shaped that the cross sectional area behind the propeller does not change materially when the longitudinal axis of the nozzle is in alignment with the axis of the propeller shaft, the inner surface of the nozzle being enlarged sharply in front of the propeller to provide an entrance opening at the front edge which is substantially larger in cross sectional area than the exit opening, the walls of the nozzle having airfoil profiles with well rounded entering edges, said profiles in the portion of the walls of the nozzle extending generally in the direction of the pivoting axis of the rudder being relatively thick with the entering edges thereof terminated at a given distance from the turning plane of the propeller blades, and the profile portions arranged generally transverse to the pivoting axis of the nozzle being more slender with the entering edges terminated at a greater distance from the turning plane of the propeller blades.

4. A steering and propelling device for a screw propelled ship comprising, a tubular nozzle surrounding the propeller with the approximate iongitudinal center thereof arranged adjacent the turning plane of the propeller blades, the internal dimension of the nozzle being such as to provide a relatively small clearance between the inner surface of the nozzle and the tips of the propeller blades, means carried by the stern of the ship for pivotably supporting the nozzle, the axis of the pivot supporting means extending through the propeller shaft and adjacent the turning plane of the propeller blades, the inner surface of the nozzle being so shaped that the cross sectional area behind the propeller does not change materially when the longitudinal axis of the nozzle is in alignment with the axis of the propeller shaft, the inner surface of the nozzle being enlarged sharply in front of the propeller to provide an entrance opening at the front edge which is substantially larger in cross sectional area than the exit opening, the walls of the nozzle having airfoil profiles with well rounded entering edges, the profiles of the side wall portions being less slender than the top and bottom portions of the nozzle, the entering edge of the more slender profile portions being located at a greater distance from the turning plane of the propeller blades than the thicker profiles, pivots carried by the slender portions of the nozzle operably associated with the pivot supporting means, and means for turning the nozzle with respect to the hull of the ship.

5. A steering and propelling device for a screw propelled ship comprising in combination, a tubular nozzle surrounding the propeller with the ranged adjacent the turning plane of the propeller blades, the internal dimension of the nozzle being such as to provide a relatively small clearance between the inner surface of the nozzle and the tipsof the propeller blades, means carried by, the stern of the ship for pivotably supporting the nozzle, the axis of the pivot supporting means extending through the propeller shaft and adjacent the turning plane of the pros peller blades, the inner surface of the nozzle being,

so shaped that the cross sectional area behind the propeller does not change materially when the longitudinal axis of the nozzle is in alignment with the axis of the propeller shaft, the inner surface of the nozzlebeing enlarged sharply in frontof the propeller to provide an entrance opening at the front edge which is substantiaily larger in cross sectional area than the exit opening, the walls of the nozzle having airfoil profiles with well rounded entering edges, and guide fins fitted to the inside of the nozzle in front of the propeller in a plane defined by the longitudinal axis of the nozzleand the pivoting axis of the nozzle.

6. A steering and propelling device for a screw propelled ship comprising in combination, a tubular nozzle surrounding the propeller with the approximate longitudinal center thereof arranged adjacent the turning plane of the propeller blades, the internaldimension of the nozzle being such as to provide a relatively small clearance between the inner surface of the nozzle and the tips of the propeller blades, means carried by the stern of the ship for pivotably supporting the nozzle; the axis of the pivot supporting means extending through the propeller shaft and adjacent the' turning plane of the propeller blades, the inner surface of the nozzle being so shaped that the cross sectional area behind the propeller does not change materially when the longitudinal axisofthenomleislntwlththeaxisof the propeller shaft, the inner surface at the nozzle being enlarged sharply in front of the propeller to provide an entrance opening at the front edge 'which is substantially larger in cross of the nozzle having airfoil profiles with well rounded entering edges, and radially arranged guide fins fitted to the inside of the nozzle in front of the propeller and behind the propeller, said fins being arranged in a plane defined by the longitudinal axis of the nozzle and the pivoting axis of the nozzle.

'l. A steering and propelling device for a screw propelled ship comprising in combination, a tubular nozzle surrounding the propeller with the approximate longitudinal center thereof arranged adjacent the turning plane of the propeller blades; the internal dimension of the nozzle being such as to provide a' relatively small clearance between the inner surface of the nozzle and the tips of the propeller blades, means carried by the stern ofthe ship for pivotably supporting the nozzle, the axis of the pivot supporting means extending through the propeller shaft and adjacent the turning plane of the propeller blades, the inner surface of the nozzle being so Shap that the cross sectional area behind the propeller does not change materially when the longitudinal axis of the nozzle is in alignment with the axis of the propeller shaft, the inner surface of the nozzle being enlarged sharply in front of the propeller to provide an entrance opening at the front edge which is substantially larger in cross sectional area than the exit opening, the walls of the nozzle having airfoil profiles with well rounded entering edges, and the outside of the nozzle having a mutually adapted shape with respect to the hull stern of the ship with a. relatively small clearance between the outer surface of the nozzle and the hull stem to providehomogeneous merging of the hull stern and the outside of the nomle.

LUDWIG KORT.

sectional area than the exit opening, the walls 

